PARIS—OSE Pharma SA, a biotechnology company based in France that is developing T-specific immunotherapy treatments against invasive and
metastatic cancers, unveiled some encouraging results of survival and T-specific immune response in the patients with brain metastases treated with the
company’s T-specific immunotherapy during the World
Conference on Lung Cancer held Sept. 6-9 in Denver.

Organized by the International Association for the Study
of Lung Cancer, the World Conference on Lung Cancer (WCLC) is the world’s largest meeting dedicated to lung cancer. The event brings together the
world’s lead physicians and researchers to present the latest breakthroughs and findings in the field.

Six
patients identified with brain metastases had been heavily pretreated; in addition to brain radiotherapy, they had previously received from one to three
different lines of chemotherapy. The study of survival under Tedopi treatment showed a median survival of 13.75 months, with extremes ranging from seven
months in a patient whose cancer was still progressing, to a survival exceeding 41 months—this patient was still alive at the end of the
study—which are particularly interesting results for this group of patients with a poor prognosis.

This
study showed a one-year survival rate for 59 percent of the group treated with Tedopi. This compares favorably with the 33-percent one-year survival rate in
patients treated with currently approved second-line treatments. The median survival in the group treated was 17 months, compared with 12 months in the group
of patients who did not receive the treatment. In addition, 25 percent of patients treated were still alive after four years, with a good quality of life,
which is important for patients suffering from principally metastatic tumors.

For five of these six patients, the
study of immune responses showed that they had actually developed a specific T cytotoxic response to at least one, and up to five, of the tested epitopes
included in Tedopi. An international patent application on this particular clinical domain was filed in November 2014.

“We are particularly pleased that these very encouraging results have been presented in the form of a poster at this prestigious conference,
with Dr. John Nemunaitis, oncologist and executive medical director of the Mary Crowley Cancer Research Centers in Dallas, as our main author. This new data
confirm the potential of Tedopi’s clinical development, which will now continue with the launch of its pivotal Phase 3 trial,” said Dr. Alain
Chatelin, chief medical officer at OSE Pharma.

OSE Pharma is a European cancer immunotherapy company with a
multi-epitope technology named Memopi that directs the body’s immune system to generate a specific cytotoxic T response to prevent cancer cell
growth.

OSE Pharma’s lead product, Tedopi, combines 10 “neo-epitopes” directed against five
tumor-associated antigens selected because their presence is linked to a poor prognosis and the severity of various cancers. These neo-epitopes generate
strong specific T cytotoxic responses that fight cancer and prevent tumor escape.

In its most advanced
application, it is about to enter a pivotal Phase 3 study in patients with advanced non-small cell lung cancer (NSCLC) who express HLA-A2 and failed first
line therapy. Tedopi has orphan drug status in the U.S. and is considered as personalized medicine in Europe in HLA-A2 positive patients.

OSE Pharma is also planning a new Phase 2 clinical trial in combination with another immunotherapy treatment in NSCLC. Also,
OSE Pharma plans a Phase 3 clinical program in 2015 in Europe and the United States in order to obtain registration in NSCLC. The study will recruit patients
with invasive/metastatic NSCLC expressing the HLA-A2 receptor (45 percent of the NSCLC population).

OSE Pharma is
currently preparing to start a Phase 3 study of Tedopi. The trial protocol is common to Europe and to the United States. The launch of the Phase 3 study of
Tedopi is planned for the second half of 2015. It will look to enroll 500 patients with invasive/metastatic NSCLC expressing the HLA-A2 receptor. Tedopi will
be used as a second-line treatment for patients for whom first-line treatments (such as chemotherapy) have not been able to control their disease.
Preparatory work and manufacturing of the clinical supplies have started. An agreement had been signed in January 2015 with Orion-Symbec, a contract research
organization based in Great Britain, for this international Phase 3 study.

Lung cancer is the deadliest cancer in the
world. In 2012, there were 1.58 million new diagnosed lung cancer cases and 1.39 million deaths from this disease globally. Despite the different treatments
available today (surgery, radiotherapy, chemotherapy, targeted therapy), the relative survival rates of these patients at metastatic stage remains very low.
Given the large incidence of NSCLC, OSE Pharma estimates that the potential global sales at peak for Tedopi for this single indication could be about €2
billion, or about $2.24 billion.